This invention concerns a device to be associated with the crankcase of a compressor utilized to compress freon refrigerant, and more particularly relates to a monitoring device adapted to detect the undesired presence of freon in said crankcase and stop the operation of the compressor when said presence of liquid freon is detected.
In various refrigeration devices utilizing a volatile freon halocarbon refrigerant, the refrigerant passes through a compression cycle which liquifies the gaseous refrigerant in preparation for a subsequent stage of evaporative cooling. Compression is achieved by means of a motordriven pistons which receives necessary oil lubrication from a crankcase. The lubricating oil confined within the crankcase is generally heated to a temperature above the saturation temperature of the refrigerant in order to vaporize away any trace amounts of liquid freon in the crankcase.
If a compressor is started with liquid refrigerant in the crankcase, there is a significant chance of catastrophic mechanical failure due to inadequate lubrication. Control systems have been disclosed which will prevent a compressor from operating when the oil temperature is too low, however, liquid phase freon may still be present because of the high pressures confined within the crankcase.
It is accordingly an object of this invention to provide a device responsive to temperature and pressure effects within the crankcase of a compressor, and capable of controlling the operation of the compressor within safe limits.
It is another object of the present invention to provide a device as in the foregoing object capable of determining when the temperature of the oil in the crankcase is low enough in relation to the pressure within the crankcase to permit the existence of liquid refrigerant within the crankcase, and to prevent operation of the compressor when such relationship is ascertained.
It is still another object of this invention to provide a device of the aforesaid nature of simple and rugged construction which may be economically manufactured and easily installed into operative association with the crankcase of a compressor.
These objects and other objects and advantages of the invention will be apparent from the following description.